Forming strip for pavement construction



Sept. 17, 1957 E. R. WOODMAN FORMING STRIP FOR PAVEMENT CONSTRUCTION Filed NOV. 9, 1953 um mmfi INVENTOR.

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ATTORNEYS.

United States FORMING STRIP FOR PAVEMENT CONSTRUCTION This invention relates to joints for pavement, roof decks and the like, and particularly to a novel strip or membrane which will form a dummy or contraction joint in pavement or the like.

An object of the invention is to provide means whereby a pavement slab or the like will crack in a controlled manner along a desired plane so as to form a contraction joint.

Another object of the invention is to provide a joint forming strip which will form a joint of the foregoing character and will seal the bottom of the joint to prevent upward penetration or pumping of moisture from the subgrade into the pavement.

It is another object of the invention to provide a joint forming strip which will prevent any water which may seep downward through the joint from penetrating into the subgrade, possible subgrade failure thus being prevented. A more specific object of the invention in this connection is to provide a joint forming strip which will carry any water which may penetrate downwardly through the joint to the extreme edges of the pavement and thereby will prevent accumulation of water in the subgrade under the pavement.

Another object of the invention is to provide a joint forming strip which will obviate any need for hand finishing of the joint and will eliminate the use of a joint filler.

Still another object is to provide a joint forming strip which may readily be manufactured, transported and installed and which will be extremely economical, durable and efiicient in its function.

Further objects of the invention will be apparent from the following description, taken with the accompanying drawings in which:

Figure 1 is a perspective view of an exemplary joint forming strip constituting an illustrative embodiment of the invention.

Figure 2 is an elevational sectional view showing the strip of Figure 1 embodied in a pavement joint, the view being taken transversely of the strip.

While a specific embodiment of the invention is shown in the drawings and will be described in detail, it will be understood that there is no intention to limit the invention to the specific form shown and described. On the contrary, the intention is to cover all equivalents, modifications and alternative constructions falling Within the spirit and scope of the invention as set forth in the speci fication and defined in the appended claims.

The illustrative embodiment of the invention comprises an elongated strip or membrane which is adapted to be supported on the subgrade 12 for a pavement slab 14. While the invention is illustrated in connection with pavement, it will be understood that it may be applied to roof decks or other similar horizontal structures. The illustrated joint strip 10 is arranged so that it will create a plane of weakness or fracture in the pavement slab 14. To this end, the joint forming strip 10 is formed with an upwardly extending narrow inverted V-shaped projecatent Q tion 16 which extends longitudinally along the center of the strip. In this instance the V-shaped projection 16 is formed by folding or crimping the central portion of the strip. However, it will be understood that the strip may be formed in the manner shown by any suitable forming process, such as casting, stamping, pressing or rolling, for example.

Provision is made for securing the joint forming strip 10 to the subgrade 12. For this purpose, a series of longitudinally spaced apertures 18 are formed adjacent the opposite edges of the strip and are adapted to receive spikes 20 or the like, which may be driven into the subgrade 12.

To conduct water along the top of the forming strip 10 to the extreme edges of the pavement, the strip 10 is formed with a pair of upwardly projecting ridges 22 located on opposite sides of the V-shaped projection 16 and extending longitudinally along the strip 10. As shown, the ridges 22 are also of inverted V-shaped form, but are of substantially less height than the central V shaped projection 16.

It is preferred to form the strip 10 of a durable metallic material, such as galvanized steel coated with hot asphalt. However, it will be understood that the strip may be formed from any reasonably durable, rigid and waterproof material, such as aluminum, other metals or plastics.

The joint forming strips 10 may be manufactured by mass production methods in a plant at any desired location and may be nested for transportation in large quantities to the pavement job. After the subgrade 12 has been brought to the desired level and the side forms for the pavement have been placed, the joint strips 10 may be laid on the subgrade between the forms at regular or desired intervals. The length of the strips 10 may be such that a single length will extend between the forms, or, for wide pavement, two or more lengths may be laid between the forms with their ends overlapping. The anchoring spikes 20 are inserted through the apertures 18 in the strips 10 and driven into the subgrade. The pavement joints may then be completed simply by pouring the pavement slab over the joint strips 10. The pavement may be made of Portland cement concrete or any other material which is subject to contraction and expansion. No special finishing of the joints is necessary. It is merely necessary to finish the surface of the pavement slab to the desired level in the usual manner.

When the pavement has hardened, the V-shaped projection 16 will form a plane of weakness in the pavement slab 14. Any cracking of the pavement slab 14, due to contraction, will occur along this plane of weakness and will result in the formation of a crack 24 extending upwardly from the V-shaped projection to the upper surface of the pavement slab. The formation of the crack 24 will relieve the stresses in the slab 14 due to contraction and will prevent further cracking.

Any water which may penetrate downwardly through the crack 24 will be positively excluded from the subgrade 12 by the joint strip 10. It will be observed that the V-shaped projection 16 and the ridges 22 are efiective to form longitudinal channels 26 in the joint strip 10. These channels will carry the water to the extreme edges of the pavement and thus will prevent subgrade failure due to penetration of surface water into the subgrade under the pavement slab 14.

The joint strip 10 will seal the bottom of the crack 24 and thus will prevent penetration or pumping of water from the subgrade into the crack 24.

It will thus be apparent the joint strip may be employed to form a pavement joint which is extremely economical, durable and efiicient in its function.

I claim as my invention:

1. A pavement joint construction, comprising a thin elongated strip having a plurality of apertures formed along its opposite edges, said strip being supported on the subgrade for the pavement, a plurality of spikes extending through said apertures into the subgrade and holding said strip in place thereon, said stripbeing formed Centrally with an upwardly extending narrow inverted V-shaped projection, said strip also being formed-with a pair of longitudinal upwardly projecting inverted V-shaped ridges spaced laterally from said projection on opposite sides thereof, and a pavement slab formed over said strip with said projection and ridges embedded in said slab, said strip extending for substantially the full Width of said slab, said V-shaped projection affording a plane of weakness along which a crack may form in said slab due to contraction, said ridges being effective to divert water seeping down through the crack to the-edges of the slab to prevent entry of the Water into the subgrade.

2. A forming strip for a joint in pavement, or the like, comprising a thin elongated strip having an upwardly extending narrow inverted V-shaped projection formed centrally and extending longitudinally thereon, said strip being adapted to be supported on the subgrade for the pavement so that the V-shaped projection will form a plane of weakness in the pavement along which a crack may form, said strip having a plurality of apertures adjacent its opposite edges for receiving spikes to secure the strip to the subgrade, and a pair of upwardly projecting inverted V-shaped ridges extending longitudinally ,On the strip on opposite sides of the V-shaped projection to form channels between the projection and the ridges along which water seeping down through the crack will be conducted to the extreme edges of the pavement.

3. A forming strip for a joint in pavement, or the like, comprising a thin elongated strip having an upwardly extending narrow inverted V-shaped projection formed centrally and extending longitudinally thereon, said strip being adapted to be supported on the subgrade for the pavement so that the V-shaped projection will form a plane of Weakness in the pavement along which a crack may form, said strip having a plurality of apertures adjacent its opposite edges for receiving spikes to secure the strip to the subgrade, and a pair of upwardly projecting ridges extending longitudinally on the strip on opposite sides of the V-shaped projection to form channels between the projection and the ridges along which water seeping down through the crack will be conducted to the extreme edges of the pavement.

References Cited in the file of this patent UNITED STATES PATENTS 312,897 Rapp Feb. 24, 1885 1,953,308 Older Apr. 3, 1934 2,243,509 Prosa May 27, 1941 2,309,538 Robertson Ian. 26, 1943 2,349,910 Methven May 30, 1944 2,589,815 Jacobson Mar. 18, 1952 

